To be honest, for me to recommend one to you I would feel the need to research the latest models and compare them. You know, do the full research (isn't that half the fun of buying a new unit though?..
I guess I would start at the replacement model for the 606 and check out the models up and down from that. Start at Onkyo's offical website, google search reviews of each model number and MOST important do what I do. I found a VERY useful research tool, the Amazon comment section. You can glean valuable information from actual owners of the product. You learn of little quirks and detail you can't get from the spec sheets on websites and sadly even reviews.
Keep in mind to take everything said on those users reviews with a grain of salt though. Some are mad for some stupid feature it has or doesn't have and have a grudge and talk $hit about it and they are just down voting it. But average out the stars and you can really get a handle on what you are buying and the options/features you have with each model. That was what I meant about buying up one level.. find the best features for YOU and then to future proof yourself, buy the model that has a few extra inputs or whiz bang features you don't even know you will need or want. Within budget of course.
Good luck and have fun. New 'toys' are always a blast to shop for. Heh